2.22 to 2.24
2.22 Plenary Answer
30 November 2010
15:19
· Note that the positive and negative charges balance for each picture
· Therefore the total charge is zero in each situation
2.23 answers
24 November 2010
10:39
· 2.23 recall that there are forces of attraction between unlike charges and forces of repulsion between like charges
Charge on ball A | Charge on ball B | Electrostatic Force |
Positive | Negative | Attract |
Positive | Positive | Repel |
Negative | Positive | Attract |
Negative | Negative | Repel |
2.24
24 November 2010
10:39
· 2.24 explain electrostatic phenomena in terms of the movement of electrons
· Charge up a student with the Van der Graph generator
· Why does their hair stand on end?
· Can you explain this in terms of the movement of electrons?
Explanation
· The electrons on each hair repel the electrons on every other hair

